Signaling overhead reduction in noma

ABSTRACT

The present disclosure relates to methods and devices for communicating based on improved signaling. A base station can transmit an indication of resources in time and frequency to a UE allocated for NOMA communication with the UE. The indication of resources can comprise a set of NA-RUs. The UE can then transmit uplink NOMA communication to the base station based on the indication of resources received from the base station. Also, the base station can transmit a compact UL resource grant via DCI, or signal the semi-static transport format configuration via RRC, to the UEs allocated for NOMA communication. The DCI or the payload of RRC signaling can be scrambled with a NOMA group RNTI, as well as comprise NOMA transmission parameters indicated by a MCS table. The UE can then transmit uplink NOMA communication to the base station based on the DCI or the RRC signaling.

CROSS REFERENCE TO RELATED APPLICATION(S)

This application is a continuation of U.S. Non-provisional applicationSer. No. 16/438,086, entitled, “SIGNALING OVERHEAD REDUCTION IN NOMA”and filed Jun. 11, 2019, which claims the benefit of U.S. ProvisionalApplication Ser. No. 62/689,048, entitled “SIGNALING OVERHEAD REDUCTIONIN NOMA” and filed on Jun. 22, 2018, each of which is expresslyincorporated by reference herein in its entirety.

TECHNICAL FIELD

The present disclosure relates generally to communication systems, andmore particularly, to methods and devices for reducing communicationsoverhead.

INTRODUCTION

Wireless communication systems are widely deployed to provide varioustelecommunication services such as telephony, video, data, messaging,and broadcasts. Typical wireless communication systems may employmultiple-access technologies capable of supporting communication withmultiple users by sharing available system resources. Examples of suchmultiple-access technologies include code division multiple access(CDMA) systems, time division multiple access (TDMA) systems, frequencydivision multiple access (FDMA) systems, orthogonal frequency divisionmultiple access (OFDMA) systems, single-carrier frequency divisionmultiple access (SC-FDMA) systems, and time division synchronous codedivision multiple access (TD-SCDMA) systems.

These multiple access technologies have been adopted in varioustelecommunication standards to provide a common protocol that enablesdifferent wireless devices to communicate on a municipal, national,regional, and even global level. An example telecommunication standardis 5G New Radio (NR). 5G NR is part of a continuous mobile broadbandevolution promulgated by Third Generation Partnership Project (3GPP) tomeet new requirements associated with latency, reliability, security,scalability (e.g., with Internet of Things (IoT)), and otherrequirements. Some aspects of 5G NR may be based on the 4G Long TermEvolution (LTE) standard. There exists a need for further improvementsin 5G NR technology. These improvements may also be applicable to othermulti-access technologies and the telecommunication standards thatemploy these technologies.

SUMMARY

The following presents a simplified summary of one or more aspects inorder to provide a basic understanding of such aspects. This summary isnot an extensive overview of all contemplated aspects, and is intendedto neither identify key or critical elements of all aspects nordelineate the scope of any or all aspects. Its sole purpose is topresent some concepts of one or more aspects in a simplified form as aprelude to the more detailed description that is presented later.

In wireless communications, e.g., Millimeter Wave (mmW) wirelesscommunication, base stations and UEs can transmit and/or receive aplurality of signals in order to facilitate communication between eachother. Such signaling may increase the overhead of the communicationsystem. If the signaling results in an increase in overhead, then anypower savings or reduction in latency may be reduced or negated. Inorder to reduce the overhead as a result of this signaling, wirelesscommunication systems can use Non-Orthogonal Multiple Access (NOMA)communication. Compared to transmissions such as Orthogonal MultipleAccess (OMA), NOMA transmissions can reduce signaling overhead in avariety of ways, such as reducing signaling for resource allocation. Byutilizing the concepts of grant-based and grant-free NOMA, the overheadof a wireless communication system can be reduced.

The present disclosure relates to methods and devices for communicatingbased on improved signaling of resources allocated for NOMA. A basestation can transmit an indication of allocated resources in time andfrequency to a UE for NOMA communication with the UE. The indication ofresources can comprise a set of NOMA resource units (NA-RUs). The UE canthen transmit uplink NOMA communication to the base station based on theindicated NA-RUs. The indication of the resources can also be based on aNOMA raster of candidate locations for the NA-RUs. Additionally, the setof NA-RUs can be indicated based on a predefined function. Theindication of the resources can also be based on a bitmap for the set ofthe NA-RUs.

Furthermore, the indication of the resources can comprise a startinglocation of the set of the NA-RUs and a number of the NA-RUs comprisedin the set. The indication can also comprise a starting location of theset of the NA-RUs, as well as an ending location of the set of theNA-RUs. The set of the NA-RUs can comprise a number of NA-RUs that arecontiguous in time and/or frequency. The set of the NA-RUs can beinterlaced in time and/or frequency within a superset of NA-RUs. Inaddition, the uplink NOMA communication may be transmitted to the basestation without an uplink grant. In this sense, the uplink NOMAcommunication can be grant-free NOMA communication or configured grantNOMA communication.

The base station can also transmit downlink control information (DCI) tothe UE for NOMA communication with the UE. The DCI can be scrambled witha NOMA group Radio Network Temporary Identifier (RNTI). The DCI can alsocomprise NOMA transmission parameters indicated by a modulation andcoding scheme (MCS) table. The UE can then transmit uplink NOMAcommunication to the base station based on the DCI. The DCI may bereceived based on a group common control channel or Remaining MinimumSystem Information (RMSI) for a common resource allocation. The DCI canalso comprise a cyclic redundancy check (CRC) that is scrambled by theNOMA group RNTI. Further, the DCI can comprise one or more NOMAtransmission parameters indicated by the MCS table. The one or more NOMAtransmission parameters can comprise a spreading factor for a NOMAtransmission, a seed of scrambling code for the NOMA transmission,and/or one or more layers for multiple branch transmission of the NOMAtransmission. The DCI can also comprise a multiple stage DCI scrambledby the NOMA group RNTI.

The base station can also transmit, and the UE can receive, a compresseduplink grant. The compressed uplink grant can be based on a table ofNOMA transport formats. The compressed uplink grant can indicate anindex for a transport format from among multiple transport formats forthe uplink NOMA communication. In addition, the compressed uplink grantcan comprise an index of at least one transport format that can bereceived through Radio Resource Control (RRC) signaling.

In an aspect of the disclosure, a method, a computer-readable medium,and an apparatus are provided for wireless communication at a UE. Theapparatus can receive an indication of resources in time and frequencyfrom a base station allocated for NOMA communication with the basestation. The indication of resources can comprise a set of NA-RUs.Moreover, the apparatus can transmit uplink NOMA communication to thebase station based on the indication of resources received from the basestation.

In another aspect of the disclosure, a method, a computer-readablemedium, and an apparatus are provided for wireless communication at abase station. The apparatus can transmit an indication of resources intime and frequency to a UE allocated for NOMA communication with the UE,wherein the indication of resources comprises a set of NA-RUs.Furthermore, the apparatus can receive uplink NOMA communication fromthe UE based on the indication of resources transmitted to the UE.

In a further aspect of the disclosure, a method, a computer-readablemedium, and an apparatus are provided for wireless communication at aUE. The apparatus can receive DCI from a base station allocated for NOMAcommunication with the base station. The DCI can be scrambled with aNOMA group RNTI. The DCI can also comprise NOMA transmission parametersindicated by an MCS table. The apparatus can also transmit uplink NOMAcommunication to the base station based on the DCI received from thebase station. In addition, the apparatus can receive a compressed uplinkgrant.

In a further aspect of the disclosure, a method, a computer-readablemedium, and an apparatus are provided for wireless communication at abase station. The apparatus can transmit DCI to a UE allocated for NOMAcommunication with the UE. The DCI can be scrambled with a NOMA groupRNTI. The DCI can also comprise NOMA transmission parameters indicatedby an MCS table. The apparatus can also receive uplink NOMAcommunication from the UE based on the DCI transmitted to the UE.Moreover, the apparatus can transmit a compressed uplink grant.

To the accomplishment of the foregoing and related ends, the one or moreaspects comprise the features hereinafter fully described andparticularly pointed out in the claims. The following description andthe annexed drawings set forth in detail certain illustrative featuresof the one or more aspects. These features are indicative, however, ofbut a few of the various ways in which the principles of various aspectsmay be employed, and this description is intended to include all suchaspects and their equivalents.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagram illustrating an example of a wireless communicationssystem and an access network.

FIGS. 2A, 2B, 2C, and 2D are diagrams illustrating examples of a DLsubframe, DL channels within the DL subframe, an UL subframe, and ULchannels within the UL subframe, respectively, for a 5G/NR framestructure.

FIG. 3 is a diagram illustrating an example of a base station and userequipment (UE) in an access network.

FIG. 4 is a diagram illustrating a base station in communication with aUE.

FIGS. 5A-5C display an example of resource configuration according tothe present disclosure.

FIG. 6 displays one example of resource allocation according to thepresent disclosure.

FIG. 7 displays another example of resource allocation according to thepresent disclosure.

FIG. 8 displays another example of resource allocation according to thepresent disclosure.

FIG. 9 displays another example of resource allocation according to thepresent disclosure.

FIG. 10 displays another example of resource allocation according to thepresent disclosure.

FIG. 11 is a diagram illustrating transmissions between a base stationand a UE.

FIG. 12 is a flowchart of a method of wireless communication.

FIG. 13 is a conceptual data flow diagram illustrating the data flowbetween different means/components in an exemplary apparatus.

FIG. 14 is a diagram illustrating an example of a hardwareimplementation for an apparatus employing a processing system.

FIG. 15 is a flowchart of a method of wireless communication.

FIG. 16 is a conceptual data flow diagram illustrating the data flowbetween different means/components in an exemplary apparatus.

FIG. 17 is a diagram illustrating an example of a hardwareimplementation for an apparatus employing a processing system.

FIG. 18 displays one example of a signaling scheme according to thepresent disclosure.

FIG. 19 is a diagram illustrating transmissions between a base stationand a UE.

FIG. 20 is a flowchart of a method of wireless communication.

FIG. 21 is a conceptual data flow diagram illustrating the data flowbetween different means/components in an exemplary apparatus.

FIG. 22 is a diagram illustrating an example of a hardwareimplementation for an apparatus employing a processing system.

FIG. 23 is a flowchart of a method of wireless communication.

FIG. 24 is a conceptual data flow diagram illustrating the data flowbetween different means/components in an exemplary apparatus.

FIG. 25 is a diagram illustrating an example of a hardwareimplementation for an apparatus employing a processing system.

DETAILED DESCRIPTION

The detailed description set forth below in connection with the appendeddrawings is intended as a description of various configurations and isnot intended to represent the only configurations in which the conceptsdescribed herein may be practiced. The detailed description includesspecific details for the purpose of providing a thorough understandingof various concepts. However, it will be apparent to those skilled inthe art that these concepts may be practiced without these specificdetails. In some instances, well known structures and components areshown in block diagram form in order to avoid obscuring such concepts.

Several aspects of telecommunication systems will now be presented withreference to various apparatus and methods. These apparatus and methodswill be described in the following detailed description and illustratedin the accompanying drawings by various blocks, components, circuits,processes, algorithms, etc. (collectively referred to as “elements”).These elements may be implemented using electronic hardware, computersoftware, or any combination thereof. Whether such elements areimplemented as hardware or software depends upon the particularapplication and design constraints imposed on the overall system.

By way of example, an element, or any portion of an element, or anycombination of elements may be implemented as a “processing system” thatincludes one or more processors. Examples of processors includemicroprocessors, microcontrollers, graphics processing units (GPUs),central processing units (CPUs), application processors, digital signalprocessors (DSPs), reduced instruction set computing (RISC) processors,systems on a chip (SoC), baseband processors, field programmable gatearrays (FPGAs), programmable logic devices (PLDs), state machines, gatedlogic, discrete hardware circuits, and other suitable hardwareconfigured to perform the various functionality described throughoutthis disclosure. One or more processors in the processing system mayexecute software. Software shall be construed broadly to meaninstructions, instruction sets, code, code segments, program code,programs, subprograms, software components, applications, softwareapplications, software packages, routines, subroutines, objects,executables, threads of execution, procedures, functions, etc., whetherreferred to as software, firmware, middleware, microcode, hardwaredescription language, or otherwise.

Accordingly, in one or more examples, the functions described may beimplemented in hardware, software, or any combination thereof. Ifimplemented in software, the functions may be stored on or encoded asone or more instructions or code on a computer-readable medium.Computer-readable media includes computer storage media. Storage mediamay be any available media that can be accessed by a computer. By way ofexample, and not limitation, such computer-readable media can comprise arandom-access memory (RAM), a read-only memory (ROM), an electricallyerasable programmable ROM (EEPROM), optical disk storage, magnetic diskstorage, other magnetic storage devices, combinations of theaforementioned types of computer-readable media, or any other mediumthat can be used to store computer executable code in the form ofinstructions or data structures that can be accessed by a computer.

FIG. 1 is a diagram illustrating an example of a wireless communicationssystem and an access network 100. The wireless communications system(also referred to as a wireless wide area network (WWAN)) includes basestations 102, UEs 104, an Evolved Packet Core (EPC) 160, and a 5G Core(5GC) 190. The base stations 102 may include macrocells (high powercellular base station) and/or small cells (low power cellular basestation). The macrocells include base stations. The small cells includefemtocells, picocells, and microcells.

The base stations 102 configured for 4G LTE (collectively referred to asEvolved Universal Mobile Telecommunications System (UMTS) TerrestrialRadio Access Network (E-UTRAN)) may interface with the EPC 160 throughbackhaul links 132 (e.g., S1 interface). The base stations 102configured for 5G NR (collectively referred to as Next Generation RAN(NG-RAN)) may interface with 5GC 190 through backhaul links 184. Inaddition to other functions, the base stations 102 may perform one ormore of the following functions: transfer of user data, radio channelciphering and deciphering, integrity protection, header compression,mobility control functions (e.g., handover, dual connectivity),inter-cell interference coordination, connection setup and release, loadbalancing, distribution for non-access stratum (NAS) messages, NAS nodeselection, synchronization, radio access network (RAN) sharing,multimedia broadcast multicast service (MBMS), subscriber and equipmenttrace, RAN information management (RIM), paging, positioning, anddelivery of warning messages. The base stations 102 may communicatedirectly or indirectly (e.g., through the EPC 160 or 5GC 190) with eachother over backhaul links 134 (e.g., X2 interface). The backhaul links134 may be wired or wireless.

The base stations 102 may wirelessly communicate with the UEs 104. Eachof the base stations 102 may provide communication coverage for arespective geographic coverage area 110. There may be overlappinggeographic coverage areas 110. For example, the small cell 102′ may havea coverage area 110′ that overlaps the coverage area 110 of one or moremacro base stations 102. A network that includes both small cell andmacrocells may be known as a heterogeneous network. A heterogeneousnetwork may also include Home Evolved Node Bs (eNBs) (HeNBs), which mayprovide service to a restricted group known as a closed subscriber group(CSG). The communication links 120 between the base stations 102 and theUEs 104 may include uplink (UL) (also referred to as reverse link)transmissions from a UE 104 to a base station 102 and/or downlink (DL)(also referred to as forward link) transmissions from a base station 102to a UE 104. The communication links 120 may use multiple-input andmultiple-output (MIMO) antenna technology, including spatialmultiplexing, beamforming, and/or transmit diversity. The communicationlinks may be through one or more carriers. The base stations 102/UEs 104may use spectrum up to Y MHz (e.g., 5, 10, 15, 20, 100, 400, etc. MHz)bandwidth per carrier allocated in a carrier aggregation of up to atotal of Yx MHz (x component carriers) used for transmission in eachdirection. The carriers may or may not be adjacent to each other.Allocation of carriers may be asymmetric with respect to DL and UL(e.g., more or fewer carriers may be allocated for DL than for UL). Thecomponent carriers may include a primary component carrier and one ormore secondary component carriers. A primary component carrier may bereferred to as a primary cell (PCell) and a secondary component carriermay be referred to as a secondary cell (SCell).

Certain UEs 104 may communicate with each other using device-to-device(D2D) communication link 158. The D2D communication link 158 may use theDL/UL WWAN spectrum. The D2D communication link 158 may use one or moresidelink channels, such as a physical sidelink broadcast channel(PSBCH), a physical sidelink discovery channel (PSDCH), a physicalsidelink shared channel (PSSCH), and a physical sidelink control channel(PSCCH). D2D communication may be through a variety of wireless D2Dcommunications systems, such as for example, FlashLinQ, WiMedia,Bluetooth, ZigBee, Wi-Fi based on the IEEE 802.11 standard, LTE, or NR.

The wireless communications system may further include a Wi-Fi accesspoint (AP) 150 in communication with Wi-Fi stations (STAs) 152 viacommunication links 154 in a 5 GHz unlicensed frequency spectrum. Whencommunicating in an unlicensed frequency spectrum, the STAs 152/AP 150may perform a clear channel assessment (CCA) prior to communicating inorder to determine whether the channel is available.

The small cell 102′ may operate in a licensed and/or an unlicensedfrequency spectrum. When operating in an unlicensed frequency spectrum,the small cell 102′ may employ NR and use the same 5 GHz unlicensedfrequency spectrum as used by the Wi-Fi AP 150. The small cell 102′,employing NR in an unlicensed frequency spectrum, may boost coverage toand/or increase capacity of the access network.

A base station 102, whether a small cell 102′ or a large cell (e.g.,macro base station), may include an eNB, gNodeB (gNB), or another typeof base station. Some base stations, such as gNB 180 may operate in atraditional sub 6 GHz spectrum, in millimeter wave (mmW) frequencies,and/or near mmW frequencies in communication with the UE 104. When thegNB 180 operates in mmW or near mmW frequencies, the gNB 180 may bereferred to as an mmW base station. Extremely high frequency (EHF) ispart of the RF in the electromagnetic spectrum. EHF has a range of 30GHz to 300 GHz and a wavelength between 1 millimeter and 10 millimeters.Radio waves in the band may be referred to as a millimeter wave. NearmmW may extend down to a frequency of 3 GHz with a wavelength of 100millimeters. The super high frequency (SHF) band extends between 3 GHzand 30 GHz, also referred to as centimeter wave. Communications usingthe mmW/near mmW radio frequency band (e.g., 3 GHz-300 GHz) hasextremely high path loss and a short range. The mmW base station 180 mayutilize beamforming 182 with the UE 104 to compensate for the extremelyhigh path loss and short range.

The base station 180 may transmit a beamformed signal to the UE 104 inone or more transmit directions 182′. The UE 104 may receive thebeamformed signal from the base station 180 in one or more receivedirections 182″. The UE 104 may also transmit a beamformed signal to thebase station 180 in one or more transmit directions. The base station180 may receive the beamformed signal from the UE 104 in one or morereceive directions. The base station 180/UE 104 may perform beamtraining to determine the best receive and transmit directions for eachof the base station 180/UE 104. The transmit and receive directions forthe base station 180 may or may not be the same. The transmit andreceive directions for the UE 104 may or may not be the same.

The EPC 160 may include a Mobility Management Entity (MME) 162, otherMMEs 164, a Serving Gateway 166, a Multimedia Broadcast MulticastService (MBMS) Gateway 168, a Broadcast Multicast Service Center (BM-SC)170, and a Packet Data Network (PDN) Gateway 172. The MME 162 may be incommunication with a Home Subscriber Server (HSS) 174. The MME 162 isthe control node that processes the signaling between the UEs 104 andthe EPC 160. Generally, the MME 162 provides bearer and connectionmanagement. All user Internet protocol (IP) packets are transferredthrough the Serving Gateway 166, which itself is connected to the PDNGateway 172. The PDN Gateway 172 provides UE IP address allocation aswell as other functions. The PDN Gateway 172 and the BM-SC 170 areconnected to the IP Services 176. The IP Services 176 may include theInternet, an intranet, an IP Multimedia Subsystem (IMS), a PS StreamingService, and/or other IP services. The BM-SC 170 may provide functionsfor MBMS user service provisioning and delivery. The BM-SC 170 may serveas an entry point for content provider MBMS transmission, may be used toauthorize and initiate MBMS Bearer Services within a public land mobilenetwork (PLMN), and may be used to schedule MBMS transmissions. The MBMSGateway 168 may be used to distribute MBMS traffic to the base stations102 belonging to a Multicast Broadcast Single Frequency Network (MBSFN)area broadcasting a particular service, and may be responsible forsession management (start/stop) and for collecting eMBMS relatedcharging information.

The 5GC 190 may include an Access and Mobility Management Function (AMF)192, other AMFs 193, a Session Management Function (SMF) 194, and a UserPlane Function (UPF) 195. The AMF 192 may be in communication with aUnified Data Management (UDM) 196. The AMF 192 is the control node thatprocesses the signaling between the UEs 104 and the 5GC 190. Generally,the AMF 192 provides QoS flow and session management. All user Internetprotocol (IP) packets are transferred through the UPF 195. The UPF 195provides UE IP address allocation as well as other functions. The UPF195 is connected to the IP Services 197. The IP Services 197 may includethe Internet, an intranet, an IP Multimedia Subsystem (IMS), a PSStreaming Service, and/or other IP services.

The base station may also be referred to as a gNB, Node B, evolved NodeB (eNB), an access point, a base transceiver station, a radio basestation, a radio transceiver, a transceiver function, a basic serviceset (BSS), an extended service set (ESS), a transmit reception point(TRP), or some other suitable terminology. The base station 102 providesan access point to the EPC 160 or 5GC 190 for a UE 104. Examples of UEs104 include a cellular phone, a smart phone, a session initiationprotocol (SIP) phone, a laptop, a personal digital assistant (PDA), asatellite radio, a global positioning system, a multimedia device, avideo device, a digital audio player (e.g., MP3 player), a camera, agame console, a tablet, a smart device, a wearable device, a vehicle, anelectric meter, a gas pump, a large or small kitchen appliance, ahealthcare device, an implant, a sensor/actuator, a display, or anyother similar functioning device. Some of the UEs 104 may be referred toas IoT devices (e.g., parking meter, gas pump, toaster, vehicles, heartmonitor, etc.). The UE 104 may also be referred to as a station, amobile station, a subscriber station, a mobile unit, a subscriber unit,a wireless unit, a remote unit, a mobile device, a wireless device, awireless communications device, a remote device, a mobile subscriberstation, an access terminal, a mobile terminal, a wireless terminal, aremote terminal, a handset, a user agent, a mobile client, a client, orsome other suitable terminology.

Referring again to FIG. 1, in certain aspects, base station 102/180 mayinclude a transmission component 198 configured to transmit anindication of resources in time and frequency to UE allocated for NOMAcommunication. Transmission component 198 can also be configured toreceive uplink NOMA communication from UE based on indication ofresources. Transmission component 198 can also be configured to transmitDCI or semi-static uplink resource grant to UE allocated for NOMAcommunication. Further, transmission component 198 can be configured totransmit compressed uplink resource grant by RRC signaling or compactDCI by PDCCH. Transmission component 198 can also be configured toreceive uplink NOMA communication from UE based on DCI or semi-staticuplink resource grant. In certain aspects, UE 104 may include areception component 199 configured to receive an indication of resourcesin time and frequency from base station allocated for NOMAcommunication. Reception component 199 can also be configured totransmit uplink NOMA communication to base station based on indicationof resources. Reception component 199 can also be configured to receiveDCI or semi-static uplink resource grant from base station allocated forNOMA communication. Additionally, reception component 199 can beconfigured to receive compressed uplink resource grant by RRC signalingor compact DCI by PDCCH. Reception component 199 can also be configuredto transmit uplink NOMA communication to base station based on DCI orsemi-static uplink resource grant.

FIG. 2A is a diagram 200 illustrating an example of a first subframewithin a 5G/NR frame structure. FIG. 2B is a diagram 230 illustrating anexample of DL channels within a 5G/NR subframe. FIG. 2C is a diagram 250illustrating an example of a second subframe within a 5G/NR framestructure. FIG. 2D is a diagram 280 illustrating an example of ULchannels within a 5G/NR subframe. The 5G/NR frame structure may be FDDin which for a particular set of subcarriers (carrier system bandwidth),subframes within the set of subcarriers are dedicated for either DL orUL, or may be TDD in which for a particular set of subcarriers (carriersystem bandwidth), subframes within the set of subcarriers are dedicatedfor both DL and UL. In the examples provided by FIGS. 2A, 2C, the 5G/NRframe structure is assumed to be TDD, with subframe 4 being configuredwith slot format 28 (with mostly DL), where D is DL, U is UL, and X isflexible for use between DL/UL, and subframe 3 being configured withslot format 34 (with mostly UL). While subframes 3, 4 are shown withslot formats 34, 28, respectively, any particular subframe may beconfigured with any of the various available slot formats 0-61. Slotformats 0, 1 are all DL, UL, respectively. Other slot formats 2-61include a mix of DL, UL, and flexible symbols. UEs are configured withthe slot format (dynamically through DL control information (DCI), orsemi-statically/statically through radio resource control (RRC)signaling) through a received slot format indicator (SFI). Note that thedescription infra applies also to a 5G/NR frame structure that is TDD.

Other wireless communication technologies may have a different framestructure and/or different channels. A frame (10 ms) may be divided into10 equally sized subframes (1 ms). Each subframe may include one or moretime slots. Subframes may also include mini-slots, which may include 7,4, or 2 symbols. Each slot may include 7 or 14 symbols, depending on theslot configuration. For slot configuration 0, each slot may include 14symbols, and for slot configuration 1, each slot may include 7 symbols.The symbols on DL may be cyclic prefix (CP) OFDM (CP-OFDM) symbols. Thesymbols on UL may be CP-OFDM symbols (for high throughput scenarios) ordiscrete Fourier transform (DFT) spread OFDM (DFT-s-OFDM) symbols (alsoreferred to as single carrier frequency-division multiple access(SC-FDMA) symbols) (for power limited scenarios; limited to a singlestream transmission). The number of slots within a subframe is based onthe slot configuration and the numerology. For slot configuration 0,different numerologies μ 0 to 5 allow for 1, 2, 4, 8, 16, and 32 slots,respectively, per subframe. For slot configuration 1, differentnumerologies 0 to 2 allow for 2, 4, and 8 slots, respectively, persubframe. Accordingly, for slot configuration 0 and numerology μ, thereare 14 symbols/slot and 2^(μ) slots/subframe. The subcarrier spacing andsymbol length/duration are a function of the numerology. The subcarrierspacing may be equal to 2^(μ)*15 kKz, where μ is the numerology 0 to 5.As such, the numerology μ=0 has a subcarrier spacing of 15 kHz and thenumerology μ=5 has a subcarrier spacing of 480 kHz. The symbollength/duration is inversely related to the subcarrier spacing. FIGS.2A-2D provide an example of slot configuration 0 with 14 symbols perslot and numerology μ=0 with 1 slot per subframe. The subcarrier spacingis 15 kHz and symbol duration is approximately 66.7 μs.

A resource grid may be used to represent the frame structure. Each timeslot includes a resource block (RB) (also referred to as physical RBs(PRBs)) that extends 12 consecutive subcarriers. The resource grid isdivided into multiple resource elements (REs). The number of bitscarried by each RE depends on the modulation scheme.

As illustrated in FIG. 2A, some of the REs carry reference (pilot)signals (RS) for the UE. The RS may include demodulation RS (DM-RS)(indicated as R_(x) for one particular configuration, where 100x is theport number, but other DM-RS configurations are possible) and channelstate information reference signals (CSI-RS) for channel estimation atthe UE. The RS may also include beam measurement RS (BRS), beamrefinement RS (BRRS), and phase tracking RS (PT-RS).

FIG. 2B illustrates an example of various DL channels within a subframeof a frame. The physical downlink control channel (PDCCH) carries DCIwithin one or more control channel elements (CCEs), each CCE includingnine RE groups (REGs), each REG including four consecutive REs in anOFDM symbol. A primary synchronization signal (PSS) may be within symbol2 of particular subframes of a frame. The PSS is used by a UE 104 todetermine subframe/symbol timing and a physical layer identity. Asecondary synchronization signal (SSS) may be within symbol 4 ofparticular subframes of a frame. The SSS is used by a UE to determine aphysical layer cell identity group number and radio frame timing. Basedon the physical layer identity and the physical layer cell identitygroup number, the UE can determine a physical cell identifier (PCI).Based on the PCI, the UE can determine the locations of theaforementioned DM-RS. The physical broadcast channel (PBCH), whichcarries a master information block (MIB), may be logically grouped withthe PSS and SSS to form a synchronization signal (SS)/PBCH block. TheMIB provides a number of RBs in the system bandwidth and a system framenumber (SFN). The physical downlink shared channel (PDSCH) carries userdata, broadcast system information not transmitted through the PBCH suchas system information blocks (SIBs), and paging messages.

As illustrated in FIG. 2C, some of the REs carry DM-RS (indicated as Rfor one particular configuration, but other DM-RS configurations arepossible) for channel estimation at the base station. The UE maytransmit DM-RS for the physical uplink control channel (PUCCH) and DM-RSfor the physical uplink shared channel (PUSCH). The PUSCH DM-RS may betransmitted in the first one or two symbols of the PUSCH. The PUCCHDM-RS may be transmitted in different configurations depending onwhether short or long PUCCHs are transmitted and depending on theparticular PUCCH format used. Although not shown, the UE may transmitsounding reference signals (SRS). The SRS may be used by a base stationfor channel quality estimation to enable frequency-dependent schedulingon the UL.

FIG. 2D illustrates an example of various UL channels within a subframeof a frame. The PUCCH may be located as indicated in one configuration.The PUCCH carries uplink control information (UCI), such as schedulingrequests, a channel quality indicator (CQI), a precoding matrixindicator (PMI), a rank indicator (RI), and HARQ ACK/NACK feedback. ThePUSCH carries data, and may additionally be used to carry a bufferstatus report (BSR), a power headroom report (PHR), and/or UCI.

FIG. 3 is a block diagram of a base station 310 in communication with aUE 350 in an access network. In the DL, IP packets from the EPC 160 maybe provided to a controller/processor 375. The controller/processor 375implements layer 3 and layer 2 functionality. Layer 3 includes a radioresource control (RRC) layer, and layer 2 includes a service dataadaptation protocol (SDAP) layer, a packet data convergence protocol(PDCP) layer, a radio link control (RLC) layer, and a medium accesscontrol (MAC) layer. The controller/processor 375 provides RRC layerfunctionality associated with broadcasting of system information (e.g.,MIB, SIBs), RRC connection control (e.g., RRC connection paging, RRCconnection establishment, RRC connection modification, and RRCconnection release), inter radio access technology (RAT) mobility, andmeasurement configuration for UE measurement reporting; PDCP layerfunctionality associated with header compression/decompression, security(ciphering, deciphering, integrity protection, integrity verification),and handover support functions; RLC layer functionality associated withthe transfer of upper layer packet data units (PDUs), error correctionthrough ARQ, concatenation, segmentation, and reassembly of RLC servicedata units (SDUs), re-segmentation of RLC data PDUs, and reordering ofRLC data PDUs; and MAC layer functionality associated with mappingbetween logical channels and transport channels, multiplexing of MACSDUs onto transport blocks (TBs), demultiplexing of MAC SDUs from TBs,scheduling information reporting, error correction through HARQ,priority handling, and logical channel prioritization.

The transmit (TX) processor 316 and the receive (RX) processor 370implement layer 1 functionality associated with various signalprocessing functions. Layer 1, which includes a physical (PHY) layer,may include error detection on the transport channels, forward errorcorrection (FEC) coding/decoding of the transport channels,interleaving, rate matching, mapping onto physical channels,modulation/demodulation of physical channels, and MIMO antennaprocessing. The TX processor 316 handles mapping to signalconstellations based on various modulation schemes (e.g., binaryphase-shift keying (BPSK), quadrature phase-shift keying (QPSK),M-phase-shift keying (M-PSK), M-quadrature amplitude modulation(M-QAM)). The coded and modulated symbols may then be split intoparallel streams. Each stream may then be mapped to an OFDM subcarrier,multiplexed with a reference signal (e.g., pilot) in the time and/orfrequency domain, and then combined together using an Inverse FastFourier Transform (IFFT) to produce a physical channel carrying a timedomain OFDM symbol stream. The OFDM stream is spatially precoded toproduce multiple spatial streams. Channel estimates from a channelestimator 374 may be used to determine the coding and modulation scheme,as well as for spatial processing. The channel estimate may be derivedfrom a reference signal and/or channel condition feedback transmitted bythe UE 350. Each spatial stream may then be provided to a differentantenna 320 via a separate transmitter 318TX. Each transmitter 318TX maymodulate an RF carrier with a respective spatial stream fortransmission.

At the UE 350, each receiver 354RX receives a signal through itsrespective antenna 352. Each receiver 354RX recovers informationmodulated onto an RF carrier and provides the information to the receive(RX) processor 356. The TX processor 368 and the RX processor 356implement layer 1 functionality associated with various signalprocessing functions. The RX processor 356 may perform spatialprocessing on the information to recover any spatial streams destinedfor the UE 350. If multiple spatial streams are destined for the UE 350,they may be combined by the RX processor 356 into a single OFDM symbolstream. The RX processor 356 then converts the OFDM symbol stream fromthe time-domain to the frequency domain using a Fast Fourier Transform(FFT). The frequency domain signal comprises a separate OFDM symbolstream for each subcarrier of the OFDM signal. The symbols on eachsubcarrier, and the reference signal, are recovered and demodulated bydetermining the most likely signal constellation points transmitted bythe base station 310. These soft decisions may be based on channelestimates computed by the channel estimator 358. The soft decisions arethen decoded and deinterleaved to recover the data and control signalsthat were originally transmitted by the base station 310 on the physicalchannel. The data and control signals are then provided to thecontroller/processor 359, which implements layer 3 and layer 2functionality.

The controller/processor 359 can be associated with a memory 360 thatstores program codes and data. The memory 360 may be referred to as acomputer-readable medium. In the UL, the controller/processor 359provides demultiplexing between transport and logical channels, packetreassembly, deciphering, header decompression, and control signalprocessing to recover IP packets from the EPC 160. Thecontroller/processor 359 is also responsible for error detection usingan ACK and/or NACK protocol to support HARQ operations.

Similar to the functionality described in connection with the DLtransmission by the base station 310, the controller/processor 359provides RRC layer functionality associated with system information(e.g., MIB, SIBs) acquisition, RRC connections, and measurementreporting; PDCP layer functionality associated with headercompression/decompression, and security (ciphering, deciphering,integrity protection, integrity verification); RLC layer functionalityassociated with the transfer of upper layer PDUs, error correctionthrough ARQ, concatenation, segmentation, and reassembly of RLC SDUs,re-segmentation of RLC data PDUs, and reordering of RLC data PDUs; andMAC layer functionality associated with mapping between logical channelsand transport channels, multiplexing of MAC SDUs onto TBs,demultiplexing of MAC SDUs from TBs, scheduling information reporting,error correction through HARQ, priority handling, and logical channelprioritization.

Channel estimates derived by a channel estimator 358 from a referencesignal or feedback transmitted by the base station 310 may be used bythe TX processor 368 to select the appropriate coding and modulationschemes, and to facilitate spatial processing. The spatial streamsgenerated by the TX processor 368 may be provided to different antenna352 via separate transmitters 354TX. Each transmitter 354TX may modulatean RF carrier with a respective spatial stream for transmission.

The UL transmission is processed at the base station 310 in a mannersimilar to that described in connection with the receiver function atthe UE 350. Each receiver 318RX receives a signal through its respectiveantenna 320. Each receiver 318RX recovers information modulated onto anRF carrier and provides the information to a RX processor 370.

The controller/processor 375 can be associated with a memory 376 thatstores program codes and data. The memory 376 may be referred to as acomputer-readable medium. In the UL, the controller/processor 375provides demultiplexing between transport and logical channels, packetreassembly, deciphering, header decompression, control signal processingto recover IP packets from the UE 350. IP packets from thecontroller/processor 375 may be provided to the EPC 160. Thecontroller/processor 375 is also responsible for error detection usingan ACK and/or NACK protocol to support HARQ operations.

At least one of the TX processor 368, the RX processor 356, and thecontroller/processor 359 may be configured to perform aspects inconnection with 198 of FIG. 1.

At least one of the TX processor 316, the RX processor 370, and thecontroller/processor 375 may be configured to perform aspects inconnection with 199 of FIG. 1.

FIG. 4 is a diagram 400 illustrating a base station 402 in communicationwith a UE 404. Referring to FIG. 4, the base station 402 may transmit abeamformed signal to the UE 404 in one or more of the directions 402 a,402 b, 402 c, 402 d, 402 e, 402 f, 402 g, 402 h. The UE 404 may receivethe beamformed signal from the base station 402 in one or more receivedirections 404 a, 404 b, 404 c, 404 d. The UE 404 may also transmit abeamformed signal to the base station 402 in one or more of thedirections 404 a-404 d. The base station 402 may receive the beamformedsignal from the UE 404 in one or more of the receive directions 402a-402 h. The base station 402/UE 404 may perform beam training todetermine the best receive and transmit directions for each of the basestation 402/UE 404. The transmit and receive directions for the basestation 402 may or may not be the same. The transmit and receivedirections for the UE 404 may or may not be the same.

In wireless communications, e.g., mmW wireless communication, basestations and UEs can transmit and/or receive a plurality of signals inorder to facilitate communication between each other. Such signaling mayrequire an increase in the overhead of the communication system. If thesignaling results in an increase in overhead, then any power savings orreduction in latency may be reduced or negated. In order to reduce theoverhead as a result of this signaling, wireless communication systemscan use NOMA communication. NOMA communication can apply to differentuse cases. As an example, NOMA communication can focus on uplinktransmissions with a base station as a receiver. In this example, thebase station can be considered an advanced receiver with interferencecancellation capabilities. A base station may comprise a gNB, forexample. NOMA transmissions may include one more payload.

As indicated above, NOMA transmission can differ from traditional OMAtransmission. In OMA transmissions, transmissions from different UEs areorthogonal to each other in time and/or frequency resources. Thus, thebase station is able to identify the UE sending the transmission basedon the time and/or frequency resources on which the transmission isreceived. In NOMA transmissions, different UEs share the time andfrequency resources, e.g., data transmissions from different UEs are notorthogonal. NOMA transmissions may comprise a first data transmissionand/or retransmissions. Such NOMA transmissions from UEs may be referredto as non-orthogonal uplink transmissions.

NOMA transmission may comprise a small payload. NOMA transmissions mayenable possible savings of systems overhead, power reduction, andlatency reduction. NOMA may be used in connection with massivemachine-type communications (mMTC), ultra-reliable low-latencycommunications (URLLC), and enhanced mobile broadband (eMBB), e.g., forcommunication with small payloads. The aspects presented herein can beapplicable to grant-based and/or grant-free transmissions. In theseinstances, NOMA transmissions can be referred to as grant-based NOMA andgrant-free NOMA.

NOMA deployments may help to reduce signaling overhead. Signalingoverhead reduction may be associated with power savings and latencyreduction. Signaling in NOMA transmissions may include control channelsignaling, e.g., PDCCH, which can carry the downlink and uplinkscheduling information.

Compared to grant-based NOMA transmissions, grant-free or configuredgrant NOMA transmissions can save the signaling overhead for ascheduling request (SR) and dynamic DCI. Grant-based transmissions canuse an uplink grant or SR, while grant-free transmissions may be sentwithout a specific uplink grant from the base station and/or SR from theUE. For grant-based NOMA, the NOMA data transmissions on the uplink maybe scheduled by an uplink grant. In some aspects, the uplink grant canbe transmitted on the PDCCH with DCI. Compared to grant-based OMAtransmission, grant-based and grant-free NOMA can help to save thesignaling overhead associated with resource allocation indication. InNOMA transmissions, even in grant-based NOMA transmissions, the NOMA UEcan share the time and frequency resources with other NOMA UEs. In someaspects, a resource allocation indication can be common to multiple NOMAUEs. As will be discussed further herein, signaling overhead reductionschemes can be used with for grant-based and grant-free NOMAtransmissions.

There are several ways that NOMA transmissions according to the presentdisclosure can reduce signaling overhead. For example, some NOMAtransmissions can allow for a more efficient way to allocate resourcesfor a first NOMA transmission, as well as any subsequentre-transmission. Shared time and/or frequency resources, e.g., for agroup of NOMA UEs, can be partitioned into NOMA-specific resource units(NA-RUs). The NA-RUs may be indexed, and the indexes may be used toindicate NOMA resources to NOMA UEs.

FIGS. 5A-5C display examples of shared time and/or frequency resources500, 510, and 520, respectively, being partitioned into NA-RUs andindexed. In one example, as shown in FIG. 5A, 12 contiguous subcarriersor physical RB (PRB) pairs can comprise an NA-RU. In another example, asshown in FIG. 5B, six interlaced subcarriers or PRB pairs can comprisean NA-RU. FIG. 5B illustrates an example of interlacing in frequency. Inanother example, as shown in FIG. 5C, six cross interlaced subcarriersor PRB pairs can comprise an NA-RU. FIG. 5C illustrates an example ofinterlacing in both time and frequency. As mentioned herein, these PRBpairs can be contiguous or interlaced in time and/or frequency. Forexample, six PRB pairs can be in a single slot along the frequencyspectrum. In other examples, a different number of PRB pairs may form anNA-RU.

As mentioned herein, NOMA transmissions can consider the signalingoverhead impact on the wireless communication system. The use of NA-RUsto indicate NOMA resources can reduce the amount of overhead used toindicate NOMA resource allocation. By compacting the way in whichresource units are indicated to the UE may reduce the amount of datathat DCI use to convey the allocation information. In addition, multipleaccess for NOMA transmissions can cross correlate time and frequencyresources, such that each of these resources can alternate with theother and/or be a contiguous block of resources. Accordingly, the timeand/or frequency resources can be indexed as contiguous or interlaced.

FIG. 6 displays an example of resource allocation 600. Specifically,FIG. 6 shows a NOMA-specific raster for the candidate locations ofNA-RUs. For example, NOMA resource allocation may be indicated based ona NOMA-specific raster for candidate locations of NA-RUs. A raster canlimit the NOMA-specific frequencies to be within a range of RBs.Additionally, a raster can enable the NOMA transmissions to focus onfrequency as well as time. The raster may provide parameters that aredefined with respect to a signal. In FIG. 6, {K₁, K₂, L} are definedwith respect to one or more synchronization signal blocks (SSBs). Forexample, in FIG. 6, K₁ indicates a frequency offset from a first SSB, K₂indicates a frequency offset from a second SSB, and L indicates a periodof time. {K₁, K₂, L} may be configurable parameters, which may be afunction of system bandwidth, the size of NR-RU, and the associatedsubcarrier spacing (SCS). The base station may indicate a raster to theUE for NOMA communication, and the UE may use the raster to determineNA-RUs for transmitting NOMA communication to the base station.

In some instances, NOMA transmissions may target small payloadstransmissions. However, other instances can allow for large payloadtransmissions. When using a raster, some NOMA transmissions can use awide load SSB transmission, e.g., where the SSB transmission utilizes awide bandwidth. Further, the amount of RBs used with the raster can beconfigured, e.g., based on the NOMA resource allocation. In someaspects, the raster can be centered around a middle frequency. Forinstance, the raster can comprise an even number of RBs centered aroundthe center RB.

In another example, a NOMA resource allocation may be indicated based ona pre-defined function. For example, a set of NA-RUs may be mapped to atime and frequency grid with respect to an SSB based on a predefinedfunction. The function may specify any of a center frequency of theNA-RUs, a subcarrier spacing, a number of PRBs within each NA-RU, etc.

FIG. 7 displays an example of resource allocation 700. In the example inFIG. 7, {f₁, f₂, L₁, L₂} may be configurable parameters, which are afunction of system bandwidth, the size of NR-RU, and SCS. For example,f₁ may provide a center frequency for a first NA-RU and L₁ may indicatetime resources for the first NA-RU. Similarly, f₂ may indicate a centerfrequency for a second NA-RU, and L₂ may indicate time resources for thesecond NA-RU. The parameters may form a hopping pattern. The hoppingpattern of {f₁, f₂, L₁, L₂} can be described by a math function orsequence, such as hash function or pseudo-noise (PN) sequence. In someaspects, the NOMA transmissions can define a related offset for the SSBtransmission. This offset can be a time variant, as well as based ondiversity gain. In this sense, NOMA transmissions can predefine thefrequency offset. For example, NOMA transmissions use an index into theHash function, which provides a location for the NOMA resources relativeto the SSB. In some aspects, the SSB transmission can be a startingpoint for determining the NA-RUs for NOMA communication by the UE.

In another example, a NOMA resource allocation may be indicated based onbitmapping. In some aspects, bitmapping may be used to index the NA-RUs.The bitmapping can help to control a channel element. In one aspect ofthe present disclosure, the DCI can carry the bitmap or bitmap index.FIG. 8 displays an example of resource allocation 800. FIG. 8illustrates an example of two NA-RU bitmaps. In some aspects utilizing abitmap, each bit can have a certain value. For a given bitmap, “0” mayindicate that the corresponding NA-RU is not allocated to NOMA UE. Suchresources might be assigned to an OMA UE. In the bitmap, “1” mayindicate that the corresponding NA-RU is allocated to a group of NOMAUE. Thus, the bitmap may provide an indication showing the UE whichNA-RUs are allocated to the group of NOMA UEs and which NA-RUs areallocated to the group of NOMA UEs. The bitmap can be time variant whenthe NA-RU resource allocation is dynamic. As mentioned above, each NA-RUcan be contiguous in a slot, and the UEs can share time and/or frequencylocations. All the UEs can monitor the transmission space. Additionally,different UEs can schedule different NA-RU index numbers. For instance,there can be simultaneous uplink NOMA transmissions going to differentNA-RUs, so bitmapping can help to allocate these simultaneoustransmissions. In some aspects, bitmapping can help to allocatemultiple, parallel NOMA transmissions. As such, bitmapping may notrequire the transmissions to be contiguous.

FIG. 9 displays an example of resource allocation 900. FIG. 9 displaysanother example in which a NOMA resource allocation may be indicatedbased on a starting location and/or a number of NA-RUs. In some aspects,the starting location can be an index or number. This option can be amore compact way to indicate the NOMA resource allocation. As displayedin FIG. 9, the base station may signal a starting location of x for theNA-RU(s) and a number Y of consecutive NA-RUs. In this example, Y NA-RUscan be allocated to the group of NOMA UEs through the indication. Thus,the UE may determine that the index of the allocated NA-RU correspondsto {x, x+1, . . . , x+Y−1}.

FIG. 10 displays an example of resource allocation 1000. FIG. 10displays an example wherein the NOMA resource allocation can beindicated based on a starting location and/or an ending location. Likethe previous example, this option can also be a compact way to indicatethe NOMA resource allocation. As displayed in FIG. 10, the base stationmay signal a starting location of x for the NA-RU(s) and an endinglocation of z for the NA-RU(s). Thus, (z−x+1) NA-RUs can be allocated toa group of NOMA UEs through the indication. Based on the indication, theUE may determine that index of the allocated NA-RU is given by {x, x+1,z}. The two options displayed in FIGS. 9 and 10 can be usedinterchangeably with one another, as they both utilize startinglocations. Accordingly, different options can be utilized to indicatethe resource allocation for NOMA transmissions. For instance, the PRBpairs can be grouped on a grid, as well as index the PRB pairs into anNA-RU number.

In some aspects, NOMA transmission herein can include additionalcommunication methods. More specifically, NOMA transmissions herein mayinclude random access channel (RACH) communication method. One exampleof NOMA communication may be a two-step RACH. Further, a communicationmessages between multiple UEs may use similar RACH resources. Forexample, a first message between multiple UEs may include a preamble anddata, such that the multiple UEs are using the same random accessresources. In some aspects, NOMA communication may utilize a number ofdifferent channels, such as a PUSCH. Additionally, NOMA communicationmay utilize HARQ, such as in response to certain channel communication,e.g., PUSCH.

FIG. 11 is a diagram 1100 illustrating transmissions between basestation 1104 and UE 1102. For instance, base station 1104 can, at 1110,transmit an indication of resources in time and frequency 1111 to UE1102 allocated for NOMA communication based on NA-RUs. The indication ofresources can comprise a set of NA-RUs. At 1120, UE 1102 receives theindication of resources in time and frequency from base station 1104.The indication of the resources can be based on a NOMA raster ofcandidate locations for the NA-RUs, e.g., as described in connectionwith the example in FIG. 6. Additionally, the set of NA-RUs can bemapped to the time frequency resource grid with respect to the SSB basedon a predefined function, e.g., as described in connection with theexample of FIG. 7. The predefined function may specify the centerfrequency of NA-RUs, the subcarrier spacing used, or the number of PRBswithin each NA-RU.

Moreover, the indication of resources can be based on a bitmap for theset of the NA-RUs, as described in connection with the example in FIG.8. The indication can also comprise a starting location of the set ofthe NA-RUs and/or a number of the NA-RUs comprised in the set, asdescribed in connection with the example in FIG. 9. Further, theindication can comprise a starting location of the set of the NA-RUsand/or an ending location of the set of the NA-RUs, as described inconnection with the example in FIG. 10. The set of the NA-RUs cancomprise a number of NA-RUs that are contiguous in time or frequency, asillustrated in the example in FIG. 5A. The set of the NA-RUs can beinterlaced in time and/or frequency within a resource grid, asillustrated in the examples in FIGS. 5A and 5B. The resource grid mayspan the entire system bandwidth in frequency and the entire slot intime, and the slot index for NR-RU can be semi-static or dynamicallyconfigured. Also, the uplink NOMA communication can be received from theUE, and multiple UEs may share the same NR-RUs in time and frequencydomain.

At 1130, UE 1102 can also transmit uplink NOMA communication 1131 tobase station 1104 based on the indication of resources. Finally, at1140, base station 1104 can receive uplink NOMA communication from theUE based on the indication of resources.

FIG. 12 is a flowchart 1200 of a method of wireless communication. Themethod may be performed by a UE (e.g., UE 104, 182, 350, 404, 1102,apparatus 1302; the processing system 1414, which may include memory1406 and which may be the entire UE 350 or a component of the UE 350,such as the TX processor 368, the RX processor 356, and/or thecontroller/processor 359) communicating with a base station (e.g., basestation 102, 180, 310, 402, 1104, apparatus 1602). Optional aspects areillustrated with a dashed line. The methods described herein can providea number of benefits, such as improving power savings and/or resourceutilization.

At 1202, the UE can receive an indication of resources in time and/orfrequency from a base station allocated for NOMA communication with theUE. For example, reception component 1304 of apparatus 1302 may receivean indication of resources in time and/or frequency from a base stationallocated for NOMA communication. The indication of resources cancomprise a set of NA-RUs. As mentioned above, the indication of theresources can be based on a NOMA raster of candidate locations for theNA-RUs, as described in connection with the example in FIG. 6. The setof NA-RUs can also be mapped to the time frequency resource grid withrespect to the SSB based on a predefined function, as described inconnection with the example in FIG. 7. The function may specify thecenter frequency of NA-RUs, the subcarrier spacing used, and/or thenumber of PRBs within each NA-RU.

Additionally, the indication of resources can be based on a bitmap forthe set of the NA-RUs, as described in connection with the example inFIG. 8. The indication can also comprise a starting location of the setof the NA-RUs and/or a number of the NA-RUs comprised in the set, asdescribed in connection with the example in FIG. 9. Moreover, theindication can comprise a starting location of the set of the NA-RUsand/or an ending location of the set of the NA-RUs, as described inconnection with the example in FIG. 10. The set of the NA-RUs cancomprise a number of NA-RUs that are contiguous in time or frequency, asillustrated in the example in FIG. 5A. The set of the NA-RUs can beinterlaced in time and/or frequency within a resource grid, asillustrated in the examples in FIGS. 5A and 5B. The resource grid mayspan the entire system bandwidth in frequency and the entire slot intime. A slot index for NR-RU can be semi-static or dynamicallyconfigured by the base station. Also, the uplink NOMA communication canbe received from the UE, and multiple UEs may share the same NA-RUs intime and frequency domain.

In addition, at 1204, the UE can transmit uplink NOMA communication tothe base station based on the indication of resources, e.g., using atleast one of the indicated NA-RUs allocated to a group of NOMA UEsincluding the UE. For example, transmission component 1306 of apparatus1302 may transmit uplink NOMA communication to the base station based onthe indication of resources.

FIG. 13 is a conceptual data flow diagram 1300 illustrating the dataflow between different means/components in an exemplary apparatus 1302.The apparatus may be a UE or a component of a UE. The apparatus includesa reception component 1304 that is configured to receive downlinkcommunication from base station 1350 and a transmission component 1306configured to transmit uplink communication to the base station 1350.The apparatus further includes a NOMA indication component 1308 that isconfigured to receive, e.g., via reception component 1304, an indicationof resources in time and frequency from a base station allocated forNOMA communication with the UE. The indication of resources can comprisea set of NA-RUs. The apparatus can also include a NOMA transmissioncomponent 1310 that is configured to transmit uplink NOMA communicationto the base station based on the indication of resources.

The apparatus may include additional components that perform each of theblocks of the algorithm in the aforementioned flowcharts of FIGS. 11 and12. As such, each block in the aforementioned flowcharts of FIGS. 11 and12 may be performed by a component and the apparatus may include one ormore of those components. The components may be one or more hardwarecomponents specifically configured to carry out the statedprocesses/algorithm, implemented by a processor configured to performthe stated processes/algorithm, stored within a computer-readable mediumfor implementation by a processor, or some combination thereof.

FIG. 14 is a diagram 1400 illustrating an example of a hardwareimplementation for an apparatus 1302′ employing a processing system1414. The processing system 1414 may be implemented with a busarchitecture, represented generally by the bus 1424. The bus 1424 mayinclude any number of interconnecting buses and bridges depending on thespecific application of the processing system 1414 and the overalldesign constraints. The bus 1424 links together various circuitsincluding one or more processors and/or hardware components, representedby the processor 1404, the components 1304, 1306, 1308, 1310, and thecomputer-readable medium/memory 1406. The bus 1424 may also link variousother circuits such as timing sources, peripherals, voltage regulators,and power management circuits, which are well known in the art, andtherefore, will not be described any further.

The processing system 1414 may be coupled to a transceiver 1410. Thetransceiver 1410 is coupled to one or more antennas 1420. Thetransceiver 1410 provides a means for communicating with various otherapparatus over a transmission medium. The transceiver 1410 receives asignal from the one or more antennas 1420, extracts information from thereceived signal, and provides the extracted information to theprocessing system 1414, specifically the reception component 1304. Inaddition, the transceiver 1410 receives information from the processingsystem 1414, specifically the transmission component 1306, and based onthe received information, generates a signal to be applied to the one ormore antennas 1420. The processing system 1414 includes a processor 1404coupled to a computer-readable medium/memory 1406. The processor 1404 isresponsible for general processing, including the execution of softwarestored on the computer-readable medium/memory 1406. The software, whenexecuted by the processor 1404, causes the processing system 1414 toperform the various functions described supra for any particularapparatus. The computer-readable medium/memory 1406 may also be used forstoring data that is manipulated by the processor 1404 when executingsoftware. The processing system 1414 further includes at least one ofthe components 1304, 1306, 1308, 1310. The components may be softwarecomponents running in the processor 1404, resident/stored in thecomputer readable medium/memory 1406, one or more hardware componentscoupled to the processor 1404, or some combination thereof. Theprocessing system 1414 may be a component of the UE 350 and may includethe memory 360 and/or at least one of the TX processor 368, the RXprocessor 356, and the controller/processor 359. Alternately, theprocessing system 1414 may comprise the entire UE, e.g., UE 350.

In one configuration, the apparatus 1302/1302′ for wirelesscommunication includes means for receiving an indication of resources intime and frequency from a base station allocated for NOMA communicationwith the base station. The indication of resources can comprise a set ofNA-RUs. The apparatus can also include means for transmitting uplinkNOMA communication to the base station based on the indication ofresources received from the base station. The aforementioned means maybe one or more of the aforementioned components of the apparatus 1302and/or the processing system 1414 of the apparatus 1302′ configured toperform the functions recited by the aforementioned means. As describedsupra, the processing system 1414 may include the TX Processor 368, theRX Processor 356, and the controller/processor 359. As such, in oneconfiguration, the aforementioned means may be the TX Processor 368, theRX Processor 356, and the controller/processor 359 configured to performthe functions recited by the aforementioned means.

FIG. 15 is a flowchart 1500 of a method of wireless communication. Themethod may be performed by a base station (e.g., base station 102, 180,310, 402, 1104, apparatus 1602; the processing system 1714, which mayinclude memory 376 and which may be the entire base station 310 or acomponent of a base station, such as the TX processor 316, the RXprocessor 370, and/or the controller/processor 375) communicating with aUE (e.g., UE 104, 182, 350, 404, 1102, apparatus 1302). Optional aspectsare illustrated with a dashed line. The methods described herein canprovide a number of benefits, such as improving power savings and/orresource utilization.

At 1502, the base station can transmit an indication of resources intime and frequency to a UE allocated for NOMA communication with thebase station. For example, transmission component 1606 of apparatus 1602may transmit an indication of resources in time and frequency to a UEallocated for NOMA communication. The indication of resources cancomprise a set of NA-RUs. As mentioned above, the indication of theresources can be based on a NOMA raster of candidate locations for theNA-RUs, as described in connection with the example in FIG. 6. The setof NA-RUs can also be mapped to the time frequency resource grid withrespect to the SSB based on a predefined function, as described inconnection with the example in FIG. 7. The function may specify thecenter frequency of NA-RUs, the subcarrier spacing used, and/or thenumber of PRBs within each NA-RU.

Further, the indication of resources can be based on a bitmap for theset of the NA-RUs, as described in connection with the example in FIG.8. The indication can also comprise a starting location of the set ofthe NA-RUs and/or a number of the NA-RUs comprised in the set, asdescribed in connection with the example in FIG. 9. Also, the indicationcan comprise a starting location of the set of the NA-RUs and an endinglocation of the set of the NA-RUs, as described in connection with theexample in FIG. 10. The set of the NA-RUs can comprise a number ofNA-RUs that are contiguous in time or frequency, as illustrated in theexample in FIG. 5A. The set of the NA-RUs can be interlaced in time orfrequency within a resource grid, as illustrated in the examples inFIGS. 5A and 5B. The resource grid may span the entire system bandwidthin frequency and the entire slot in time, and the slot index for NR-RUcan be semi-static or dynamically configured. The uplink NOMAcommunication can be received from the UE, and multiple UEs share thesame NR-RUs in time and frequency domain.

Finally, at 1504, the base station can receive uplink NOMA communicationfrom the UE based on the indication of resources. For example, receptioncomponent 1604 of apparatus 1602 may receive uplink NOMA communicationfrom the UE based on the indication of resources.

FIG. 16 is a conceptual data flow diagram 1600 illustrating the dataflow between different means/components in an exemplary apparatus 1602.The apparatus may be a base station or a component of a base station.The apparatus includes a transmission component 1606 that is configuredto transmit an indication of resources to the UE 1650. The apparatusfurther includes NOMA transmission component 1610 that is configured totransmit, e.g., via transmission component 1604, an indication ofresources in time and frequency to UE 1650 allocated for NOMAcommunication with the base station. The indication of resources cancomprise a set of NA-RUs. The apparatus can also include a receptioncomponent 1604 that is configured to receive uplink communication fromUE 1350. The apparatus can further include NOMA indication component1608 that is configured to receive, e.g., via reception component 1604uplink NOMA communication from the UE based on the indication ofresources.

The apparatus may include additional components that perform each of theblocks of the algorithm in the aforementioned flowcharts of FIGS. 11 and15. As such, each block in the aforementioned flowcharts of FIGS. 11 and15 may be performed by a component and the apparatus may include one ormore of those components. The components may be one or more hardwarecomponents specifically configured to carry out the statedprocesses/algorithm, implemented by a processor configured to performthe stated processes/algorithm, stored within a computer-readable mediumfor implementation by a processor, or some combination thereof.

FIG. 17 is a diagram 1700 illustrating an example of a hardwareimplementation for an apparatus 1602′ employing a processing system1714. The processing system 1714 may be implemented with a busarchitecture, represented generally by the bus 1724. The bus 1724 mayinclude any number of interconnecting buses and bridges depending on thespecific application of the processing system 1714 and the overalldesign constraints. The bus 1724 links together various circuitsincluding one or more processors and/or hardware components, representedby the processor 1704, the components 1604, 1606, 1608, 1610, and thecomputer-readable medium/memory 1706. The bus 1724 may also link variousother circuits such as timing sources, peripherals, voltage regulators,and power management circuits, which are well known in the art, andtherefore, will not be described any further.

The processing system 1714 may be coupled to a transceiver 1710. Thetransceiver 1710 is coupled to one or more antennas 1720. Thetransceiver 1710 provides a means for communicating with various otherapparatus over a transmission medium. The transceiver 1710 receives asignal from the one or more antennas 1720, extracts information from thereceived signal, and provides the extracted information to theprocessing system 1714, specifically the reception component 1606. Inaddition, the transceiver 1710 receives information from the processingsystem 1714, specifically the transmission component 1604, and based onthe received information, generates a signal to be applied to the one ormore antennas 1720. The processing system 1714 includes a processor 1704coupled to a computer-readable medium/memory 1706. The processor 1704 isresponsible for general processing, including the execution of softwarestored on the computer-readable medium/memory 1706. The software, whenexecuted by the processor 1704, causes the processing system 1714 toperform the various functions described supra for any particularapparatus. The computer-readable medium/memory 1706 may also be used forstoring data that is manipulated by the processor 1704 when executingsoftware. The processing system 1714 further includes at least one ofthe components 1604, 1606, 1608, 1610. The components may be softwarecomponents running in the processor 1704, resident/stored in thecomputer readable medium/memory 1706, one or more hardware componentscoupled to the processor 1704, or some combination thereof. Theprocessing system 1714 may be a component of the base station 310 andmay include the memory 376 and/or at least one of the TX processor 316,the RX processor 370, and the controller/processor 375. Alternately, theprocessing system 1714 may comprise the entire base station, e.g., basestation 310.

In one configuration, the apparatus 1602/1602′ for wirelesscommunication includes means for transmitting an indication of resourcesin time and frequency to a UE allocated for NOMA communication with theUE. The indication of resources can comprise a set of NA-RUs. Theapparatus can also include means for receiving uplink NOMA communicationfrom the UE based on the indication of resources transmitted to the UE.The aforementioned means may be one or more of the aforementionedcomponents of the apparatus 1602 and/or the processing system 1714 ofthe apparatus 1602′ configured to perform the functions recited by theaforementioned means. As described supra, the processing system 1714 mayinclude the TX Processor 316, the RX Processor 370, and thecontroller/processor 375. As such, in one configuration, theaforementioned means may be the TX Processor 316, the RX Processor 370,and the controller/processor 375 configured to perform the functionsrecited by the aforementioned means.

In addition to, or alternatively to, the aspects described in connectionwith FIGS. 5A-11, the present disclosure may reduce signaling overheadby compacting the DCI for NOMA communication and/or by utilizing acompressed form of configured grant for NOMA communication. In someaspects, a configured grant transmission can use an RRC configurationrather than in dynamic DCI in the PDCCH.

Additionally, a group RNTI for a group of NOMA UEs can be introduced.Thus, the RNTI may not be UE-specific, but rather group-specific andcommon to all NOMA UEs within a group. The group of NOMA UEs may sharethe same NA-RUs. Some aspects can also use a group RNTI to scramble ormask part of the CRC. As mentioned herein, NOMA transmissions can sharetime and frequency resources. Along these lines, most NOMA transmissionschemes can share a common feature. For example, when using a scramblingbased NOMA transmission, the scrambling length can be the same for allNOMA transmissions. These common features of NOMA transmissions canprovide a basis for the compact signaling.

FIG. 18 displays an example of a signaling scheme 1800. FIG. 18 displaysone example of compacting the DCI that can be supported in NOMAtransmissions in the present disclosure in order to reduce the signalingoverhead of dynamic DCI. In one aspect, a group common PDCCH can bereused. As shown in FIG. 18, the RMSI for a common resource allocationcan be reused. The CRC for the group common PDCCH and/or RMSI for commonresource allocation can be scrambled by NOMA group RNTI. In someaspects, a group common PDCCH can be used, so each UE in the cell canmonitor the search space for the PDCCH. Additionally, in some aspectsthe payload size of the group common PDCCH can be limited, so the commonor shared resources can be used in order to keep the payload size low. Amulti-cast or broadcast signal may be used to carry the common resourceallocation. Accordingly, some aspects can consider a group common PDCCHfor the common resource allocation. In other aspects, the PDCCH and RMSIcan be payload based, and the CRC for both the PDCCH and RMSI can bescrambled by the NOMA group RNTI.

In another aspect, a modified DCI format may be used for NOMA, inaddition to a MCS table comprising NOMA specific transmissionparameters. As shown in FIG. 18, NOMA specific transmission parameterscan be included with the MCS table entries. For instance, these NOMAspecific transmission parameters can include any of a spreading factor,a seed of scrambling code, and layers for multi-branch transmission.Some entries of the new MCS table can be customized for NOMA specifictransmission parameters. For example, the MCS table can include an entryfor a spreading factor, a seed of scrambling code, or layers formulti-branch transmission.

In yet another aspect, a multi-stage DCI scrambled by a NOMA group RNTImay be used. In some aspects, the system bandwidth can be wide, so thatthe system bandwidth can accommodate both NOMA and OMA transmissions. Acommon subspace may be used to carry the NOMA specific group commonPDCCH. The subspace can be monitored, whether using OMA or NOMA UEs.From power savings perspective, these types of transmissions can be usedwith NOMA UEs, as OMA UEs may not have a grant. Additionally, thesetransmissions can be performed in multiple steps. Further, this canenable power savings for OMA UEs, as once OMA UEs detect the first stageDCI, then the wireless system can stop the signal processing and savepower. A NOMA UE that is able to decode the first stage of the DCI basedon the NOMA group RNTI, will continue to receive and decode theadditional stages of the multi-stage DCI.

In another aspect of the present disclosure, in order to reduce thepayload size of a configured grant for the first transmissions and HARQre-transmissions, a compressed form of a configured grant can besupported. In some aspects, configured grant or grant-free transmissionscan be carried by RRC and choose the first transmission. As mentionedabove, in NOMA transmissions, the first transmission and there-transmissions can be configured. Accordingly, the configured grantcan cover the first transmission and any re-transmissions. The grant tothe UE may reference a table of transport formats applicable to NOMA.For example, the UE may use a new lookup table to identify the transportformat for the UE from the grant. A lookup table may be built betweenthe first and re-transmission, e.g., in order to simplify the signaling.For example, if a pre-configuration includes a first transmission usinga certain spreading factor and a re-transmission using a largerspreading factor, aspects presented herein can simplify this processthrough use of a lookup table. Further, some aspects can use a bit inthe RRC payload to identify whether the transmissions are activated ordeactivated.

In another aspect, a compressed form of configured grant can utilize anindex or number the transport formats available to different NOMAschemes. For instance, the possible combinations for the firsttransmission and re-transmissions can be enumerated. For example, an MCSor NOMA specific transmission scheme can have a table to list thepossible combinations. The grant to the UE may comprise and index, andthe UE can use an index to identify the corresponding transport format.Additionally, a compressed form of configured grant can select one or asubset of transport formats, and transmit the index in the payload ofRRC signaling. In some aspects, the index can be of the correspondingtransport format. As such, in these aspects, the index can betransmitted, not the details the payload of RRC signaling. As the indexmay need to be transmitted to the UE in the grant, this is an efficientway to signal the information for the first and re-transmissions.

FIG. 19 is a diagram 1900 illustrating transmissions between basestation 1904 and UE 1902. For instance, base station 1904 can transmit1910 DCI or a semi-static uplink resource grant 1911 to UE 1902allocated for NOMA communication. A payload of the DCI or thesemi-static uplink resource grant can be scrambled with a NOMA groupRNTI or comprise NOMA transmission parameters indicated by an extendedMCS table. UE 1902 can receive 1920 the DCI or semi-static uplinkresource grant from base station 1904 allocated for NOMA communication.

The DCI can be received based on at least one of a group common controlchannel or RMSI for a common resource allocation. The DCI may alsocomprise a CRC that is scrambled by the NOMA group RNTI. Additionally,the DCI can comprise one or more NOMA transmission parameters indicatedby the extended MCS table, as described in connection with the examplein FIG. 18. The one or more NOMA transmission parameters can comprise atleast one of a spreading factor for a NOMA transmission, a seed ofscrambling code for the NOMA transmission, and one or more layers formultiple branch transmission of the NOMA transmission, as mentionedabove in connection with the example in FIG. 18. The DCI can alsocomprise a multiple stage DCI scrambled by the NOMA group RNTI.

Base station 1904 can also transmit 1930 a compressed uplink resourcegrant by RRC signaling or a compact DCI by PDCCH 1931. In turn, UE 1902can receive 1940 the compressed uplink resource grant by RRC signalingor compact DCI by PDCCH. The compressed uplink resource grant can bebased on a table of NOMA transport formats. Also, the compressed uplinkresource grant can indicate an index for a transport format from amongmultiple transport formats for the uplink NOMA communication. Further,the compressed uplink resource grant can comprise an index of at leastone transport format that is received through RRC signaling.

UE 1902 can also transmit 1950 uplink NOMA communication 1951 to thebase station based on DCI or a semi-static uplink resource grant.Finally, base station 1904 can receive 1960 uplink NOMA communicationfrom the UE based on the DCI or semi-static uplink resource grant.

FIG. 20 is a flowchart 2000 of a method of wireless communication. Themethod may be performed by a UE (e.g., UE 104, 182, 350, 404, 1902,apparatus 2102; the processing system 2214, which may include memory2206 and which may be the entire UE 350 or a component of the UE 350,such as the TX processor 368, the RX processor 356, and/or thecontroller/processor 359) communicating with a base station (e.g., basestation 102, 180, 310, 402, 1904, apparatus 2402). Optional aspects areillustrated with a dashed line. The methods described herein can providea number of benefits, such as improving power savings and/or resourceutilization.

At 2002, the UE can receive DCI or semi-static uplink resource grantfrom the base station allocated for NOMA communication. For example,reception component 2104 of apparatus 2102 may receive DCI orsemi-static uplink resource grant from the base station allocated forNOMA communication. A payload of the DCI or the semi-static uplinkresource grant can be scrambled with a NOMA group RNTI or comprise NOMAtransmission parameters indicated by an extended MCS table, as describedin connection with the example in FIG. 18. The DCI can be received basedon at least one of a group common control channel or RMSI for a commonresource allocation. The DCI also comprise a CRC that is scrambled bythe NOMA group RNTI. Further, the DCI can comprise one or more NOMAtransmission parameters indicated by the extended MCS table. The one ormore NOMA transmission parameters can comprise at least one of aspreading factor for a NOMA transmission, a seed of scrambling code forthe NOMA transmission, and one or more layers for multiple branchtransmission of the NOMA transmission, as mentioned above in connectionwith the example in FIG. 18. The DCI can also comprise a multiple stageDCI scrambled by the NOMA group RNTI.

At 2004, the UE can receive the compressed uplink resource grant by RRCsignaling or compact DCI by PDCCH. For example, reception component 2104of apparatus 2102 may receive the compressed uplink resource grant byRRC signaling or compact DCI by PDCCH. The compressed uplink resourcegrant can be based on a table of NOMA transport formats. Also, thecompressed uplink resource grant can indicate an index for a transportformat from among multiple transport formats for the uplink NOMAcommunication. The compressed uplink resource grant can comprise anindex of at least one transport format that is received through RRCsignaling.

Finally, at 2006, the UE can transmit uplink NOMA communication to thebase station based on DCI or a semi-static uplink resource grant. Forexample, transmission component 2106 of apparatus 2102 may transmituplink NOMA communication to the base station based on DCI or asemi-static uplink resource grant.

FIG. 21 is a conceptual data flow diagram 2100 illustrating the dataflow between different means/components in an exemplary apparatus 2102.The apparatus may be a UE or a component of a UE. The apparatus caninclude a reception component 2104 that is configured to receive DCI orsemi-static uplink resource grant from a base station allocated for NOMAcommunication. NOMA compression component 2110 can also be configured toreceive compressed uplink resource grant by RRC signaling. NOMAcompaction component 2108 can be configured to receive compact DCI byPDCCH. The apparatus can also include a transmission component 2106 thatis configured to transmit uplink communication to base station 2150. Theapparatus can also include a NOMA transmission component 2112 that isconfigured to transmit uplink NOMA communication to base station basedon DCI or semi-static uplink resource grant.

The apparatus may include additional components that perform each of theblocks of the algorithm in the aforementioned flowcharts of FIGS. 19 and20. As such, each block in the aforementioned flowcharts of FIGS. 19 and20 may be performed by a component and the apparatus may include one ormore of those components. The components may be one or more hardwarecomponents specifically configured to carry out the statedprocesses/algorithm, implemented by a processor configured to performthe stated processes/algorithm, stored within a computer-readable mediumfor implementation by a processor, or some combination thereof.

FIG. 22 is a diagram 2200 illustrating an example of a hardwareimplementation for an apparatus 2102′ employing a processing system2214. The processing system 2214 may be implemented with a busarchitecture, represented generally by the bus 2224. The bus 2224 mayinclude any number of interconnecting buses and bridges depending on thespecific application of the processing system 2214 and the overalldesign constraints. The bus 2224 links together various circuitsincluding one or more processors and/or hardware components, representedby the processor 2204, the components 2104, 2106, 2108, 2110, 2112, andthe computer-readable medium/memory 2206. The bus 2224 may also linkvarious other circuits such as timing sources, peripherals, voltageregulators, and power management circuits, which are well known in theart, and therefore, will not be described any further.

The processing system 2214 may be coupled to a transceiver 2210. Thetransceiver 2210 is coupled to one or more antennas 2220. Thetransceiver 2210 provides a means for communicating with various otherapparatus over a transmission medium. The transceiver 2210 receives asignal from the one or more antennas 2220, extracts information from thereceived signal, and provides the extracted information to theprocessing system 2214, specifically the reception component 2104. Inaddition, the transceiver 2210 receives information from the processingsystem 2214, specifically the transmission component 2106, and based onthe received information, generates a signal to be applied to the one ormore antennas 2220. The processing system 2214 includes a processor 2204coupled to a computer-readable medium/memory 2206. The processor 2204 isresponsible for general processing, including the execution of softwarestored on the computer-readable medium/memory 2206. The software, whenexecuted by the processor 2204, causes the processing system 2214 toperform the various functions described supra for any particularapparatus. The computer-readable medium/memory 2206 may also be used forstoring data that is manipulated by the processor 2204 when executingsoftware. The processing system 2214 further includes at least one ofthe components 2104, 2106, 2108, 2110, 2112. The components may besoftware components running in the processor 2204, resident/stored inthe computer readable medium/memory 2206, one or more hardwarecomponents coupled to the processor 2204, or some combination thereof.The processing system 2214 may be a component of the UE 350 and mayinclude the memory 360 and/or at least one of the TX processor 368, theRX processor 356, and the controller/processor 359. Alternatively, theprocessing system 2214 may comprise the entire UE, e.g., UE 350.

In one configuration, the apparatus 2102/2102′ for wirelesscommunication includes means for receiving DCI or a semi-static uplinkresource grant from a base station allocated for NOMA communication withthe base station. The DCI can be scrambled with a NOMA group RNTI orcomprises NOMA transmission parameters indicated by an extended MCStable. The apparatus can also include means for receiving a compact DCIsignaled by PDCCH or a compressed uplink resource grant signaled by aRRC. The apparatus can also include means for transmitting uplink NOMAcommunication to the base station based on the DCI or a semi-staticuplink resource grant received from the base station. The aforementionedmeans may be one or more of the aforementioned components of theapparatus 2102 and/or the processing system 2214 of the apparatus 2102′configured to perform the functions recited by the aforementioned means.As described supra, the processing system 2214 may include the TXProcessor 368, the RX Processor 356, and the controller/processor 359.As such, in one configuration, the aforementioned means may be the TXProcessor 368, the RX Processor 356, and the controller/processor 359configured to perform the functions recited by the aforementioned means.

FIG. 23 is a flowchart 2300 of a method of wireless communication. Themethod may be performed by a base station (e.g., base station 102, 180,310, 402, 1904, apparatus 2402; the processing system 2514, which mayinclude memory 376 and which may be the entire base station 310 or acomponent of a base station, such as the TX processor 316, the RXprocessor 370, and/or the controller/processor 375) communicating with aUE (e.g., UE 104, 182, 350, 404, 1902, apparatus 2102). Optional aspectsare illustrated with a dashed line. The methods described herein canprovide a number of benefits, such as improving power savings and/orresource utilization.

At 2302, the base station can transmit DCI or semi-static uplinkresource grant to the UE allocated for NOMA communication. For example,transmission component 2406 of apparatus 2402 may transmit DCI orsemi-static uplink resource grant to the UE allocated for NOMAcommunication. A payload of the DCI or the semi-static uplink resourcegrant can be scrambled with a NOMA group RNTI or comprise NOMAtransmission parameters indicated by an extended MCS table, as describedin connection with the example in FIG. 18. The DCI can be received basedon at least one of a group common control channel or RMSI for a commonresource allocation. The DCI also comprise a CRC that is scrambled bythe NOMA group RNTI. Also, the DCI can comprise one or more NOMAtransmission parameters indicated by the extended MCS table. The one ormore NOMA transmission parameters can comprise at least one of aspreading factor for a NOMA transmission, a seed of scrambling code forthe NOMA transmission, and one or more layers for multiple branchtransmission of the NOMA transmission, as mentioned above in connectionwith the example in FIG. 18. The DCI can also comprise a multiple stageDCI scrambled by the NOMA group RNTI.

At 2304, the base station can transmit the compressed uplink resourcegrant by RRC signaling or compact DCI by PDCCH. For example,transmission component 2406 of apparatus 2402 may transmit thecompressed uplink resource grant by RRC signaling or compact DCI byPDCCH. The compressed uplink resource grant can be based on a table ofNOMA transport formats. Further, the compressed uplink resource grantcan indicate an index for a transport format from among multipletransport formats for the uplink NOMA communication. The compresseduplink resource grant can comprise an index of at least one transportformat that is received through RRC signaling.

Finally, at 2306, the base station can receive uplink NOMA communicationfrom the UE based on DCI or a semi-static uplink resource grant. Forexample, reception component 2404 of apparatus 2402 may receive uplinkNOMA communication from the UE based on DCI or a semi-static uplinkresource grant.

FIG. 24 is a conceptual data flow diagram 2400 illustrating the dataflow between different means/components in an exemplary apparatus 2402.The apparatus may be a base station or a component of a base station.The apparatus includes a transmission component 2406 that is configuredto transmit DCI or semi-static uplink resource grant to a UE allocatedfor NOMA communication. NOMA transmission component 2412 can also beconfigured to transmit compressed uplink resource grant by RRC signalingor compact DCI by PDCCH. The apparatus can also include a receptioncomponent 2404 that is configured to receive uplink communication fromUE 2450. NOMA compaction component 2408 can be configured to receiveuplink NOMA communication from the UE based on DCI. NOMA compressioncomponent 2410 can also be configured to receive uplink NOMAcommunication from the UE based on semi-static uplink resource grant.

The apparatus may include additional components that perform each of theblocks of the algorithm in the aforementioned flowcharts of FIGS. 19 and23. As such, each block in the aforementioned flowcharts of FIGS. 19 and23 may be performed by a component and the apparatus may include one ormore of those components. The components may be one or more hardwarecomponents specifically configured to carry out the statedprocesses/algorithm, implemented by a processor configured to performthe stated processes/algorithm, stored within a computer-readable mediumfor implementation by a processor, or some combination thereof.

FIG. 25 is a diagram 2500 illustrating an example of a hardwareimplementation for an apparatus 2402′ employing a processing system2514. The processing system 2514 may be implemented with a busarchitecture, represented generally by the bus 2524. The bus 2524 mayinclude any number of interconnecting buses and bridges depending on thespecific application of the processing system 2514 and the overalldesign constraints. The bus 2524 links together various circuitsincluding one or more processors and/or hardware components, representedby the processor 2504, the components 2404, 2406, 2408, 2410, 2412, andthe computer-readable medium/memory 2506. The bus 2524 may also linkvarious other circuits such as timing sources, peripherals, voltageregulators, and power management circuits, which are well known in theart, and therefore, will not be described any further.

The processing system 2514 may be coupled to a transceiver 2510. Thetransceiver 2510 is coupled to one or more antennas 2520. Thetransceiver 2510 provides a means for communicating with various otherapparatus over a transmission medium. The transceiver 2510 receives asignal from the one or more antennas 2520, extracts information from thereceived signal, and provides the extracted information to theprocessing system 2514, specifically the reception component 2406. Inaddition, the transceiver 2510 receives information from the processingsystem 2514, specifically the transmission component 2404, and based onthe received information, generates a signal to be applied to the one ormore antennas 2520. The processing system 2514 includes a processor 2504coupled to a computer-readable medium/memory 2506. The processor 2504 isresponsible for general processing, including the execution of softwarestored on the computer-readable medium/memory 2506. The software, whenexecuted by the processor 2504, causes the processing system 2514 toperform the various functions described supra for any particularapparatus. The computer-readable medium/memory 2506 may also be used forstoring data that is manipulated by the processor 2504 when executingsoftware. The processing system 2514 further includes at least one ofthe components 2404, 2406, 2408, 2410, 2412. The components may besoftware components running in the processor 2504, resident/stored inthe computer readable medium/memory 2506, one or more hardwarecomponents coupled to the processor 2504, or some combination thereof.The processing system 2514 may be a component of the base station 310and may include the memory 376 and/or at least one of the TX processor316, the RX processor 370, and the controller/processor 375.Alternatively, the processing system 2514 may comprise the entire basestation, e.g., base station 310.

In one configuration, the apparatus 2402/2402′ for wirelesscommunication includes means for transmitting DCI or a semi-staticuplink resource grant to a UE allocated for NOMA communication with theUE. A payload of the DCI or the semi-static uplink resource grant can bescrambled with a NOMA group RNTI or comprises NOMA transmissionparameters indicated by an extended MCS table. The apparatus can alsoinclude means for transmitting a compressed uplink resource grant by RRCsignaling or a compact DCI by a PDCCH. The apparatus can also includemeans for receiving uplink NOMA communication from the UE. Theaforementioned means may be one or more of the aforementioned componentsof the apparatus 2402 and/or the processing system 2514 of the apparatus2402′ configured to perform the functions recited by the aforementionedmeans. As described supra, the processing system 2514 may include the TXProcessor 316, the RX Processor 370, and the controller/processor 375.As such, in one configuration, the aforementioned means may be the TXProcessor 316, the RX Processor 370, and the controller/processor 375configured to perform the functions recited by the aforementioned means.

It is understood that the specific order or hierarchy of blocks in theprocesses/flowcharts disclosed is an illustration of exemplaryapproaches. Based upon design preferences, it is understood that thespecific order or hierarchy of blocks in the processes/flowcharts may berearranged. Further, some blocks may be combined or omitted. Theaccompanying method claims present elements of the various blocks in asample order, and are not meant to be limited to the specific order orhierarchy presented.

The previous description is provided to enable any person skilled in theart to practice the various aspects described herein. Variousmodifications to these aspects will be readily apparent to those skilledin the art, and the generic principles defined herein may be applied toother aspects. Thus, the claims are not intended to be limited to theaspects shown herein, but is to be accorded the full scope consistentwith the language claims, wherein reference to an element in thesingular is not intended to mean “one and only one” unless specificallyso stated, but rather “one or more.” The word “exemplary” is used hereinto mean “serving as an example, instance, or illustration.” Any aspectdescribed herein as “exemplary” is not necessarily to be construed aspreferred or advantageous over other aspects. Unless specifically statedotherwise, the term “some” refers to one or more. Combinations such as“at least one of A, B, or C,” “one or more of A, B, or C,” “at least oneof A, B, and C,” “one or more of A, B, and C,” and “A, B, C, or anycombination thereof” include any combination of A, B, and/or C, and mayinclude multiples of A, multiples of B, or multiples of C. Specifically,combinations such as “at least one of A, B, or C,” “one or more of A, B,or C,” “at least one of A, B, and C,” “one or more of A, B, and C,” and“A, B, C, or any combination thereof” may be A only, B only, C only, Aand B, A and C, B and C, or A and B and C, where any such combinationsmay contain one or more member or members of A, B, or C. All structuraland functional equivalents to the elements of the various aspectsdescribed throughout this disclosure that are known or later come to beknown to those of ordinary skill in the art are expressly incorporatedherein by reference and are intended to be encompassed by the claims.Moreover, nothing disclosed herein is intended to be dedicated to thepublic regardless of whether such disclosure is explicitly recited inthe claims. The words “module,” “mechanism,” “element,” “device,” andthe like may not be a substitute for the word “means.” As such, no claimelement is to be construed as a means plus function unless the elementis expressly recited using the phrase “means for.”

What is claimed is:
 1. A method of wireless communication at a userequipment (UE), comprising: receiving, from a base station, anindication of resources in time and frequency allocated for randomaccess channel (RACH) communication with the base station, wherein theindication of resources comprises a set of RACH resources, wherein theset of RACH resources is mapped to a time frequency resource grid withrespect to a synchronization signal block (SSB) based on at least one ofa center frequency of a RACH resource or a number of physical resourceblocks (PRBs) within each RACH resource in the set of RACH resources,wherein the indication of resources is based on a mapping index for theset of RACH resources mapped to the time frequency resource grid andindexed in a sequential order, wherein the mapping index maps at leastone of the set of RACH resources to the time frequency resource grid;and transmitting, to the base station, a message A (msgA) of a two-stepRACH procedure based on the indication of resources received from thebase station.
 2. The method of claim 1, wherein the indication ofresources is based on a raster of candidate locations for the set ofRACH resources.
 3. The method of claim 1, wherein the indicationcomprises a starting location of the set of RACH resources and a numberof the RACH resources comprised in the set of RACH resources.
 4. Themethod of claim 1, wherein the indication comprises a starting locationof the set of RACH resources and an ending location of the set of RACHresources.
 5. The method of claim 1, wherein the set of RACH resourcescomprises a number of the RACH resources that are contiguous in time orfrequency.
 6. The method of claim 1, wherein the set of RACH resourcesis interlaced in time or frequency within a resource grid spanning asystem bandwidth in frequency and at least one slot in time.
 7. Themethod of claim 1, wherein the msgA of the two-step RACH procedure istransmitted to the base station, and multiple UEs share the set of RACHresources in a time and frequency domain.
 8. A method of wirelesscommunication at a base station, comprising: transmitting, to a userequipment (UE), an indication of resources in time and frequencyallocated for random access channel (RACH) communication with the UE,wherein the indication of resources comprises a set of RACH resources,wherein the set of RACH resources is mapped to a time frequency resourcegrid with respect to a synchronization signal block (SSB) based on atleast one of a center frequency of a RACH resource or a number ofphysical resource blocks (PRBs) within each RACH resource in the set ofRACH resources, wherein the indication of resources is based on amapping index for the set of RACH resources mapped to the time frequencyresource grid and indexed in a sequential order, wherein the mappingindex maps at least one of the set of RACH resources to the timefrequency resource grid; and receiving, from the UE, a message A (msgA)of a two-step RACH procedure based on the indication of resourcestransmitted to the UE.
 9. The method of claim 8, wherein the indicationof resources is based on a raster of candidate locations for the set ofRACH resources.
 10. The method of claim 8, wherein the indicationcomprises a starting location of the set of RACH resources and a numberof the RACH resources comprised in the set of RACH resources.
 11. Themethod of claim 8, wherein the indication comprises a starting locationof the set of RACH resources and an ending location of the set of RACHresources.
 12. The method of claim 8, wherein the set of RACH resourcescomprises a number of the RACH resources that are contiguous in time orfrequency.
 13. The method of claim 8, wherein the set of RACH resourcesis interlaced in time or frequency within a resource grid spanning asystem bandwidth in frequency and at least one slot in time.
 14. Themethod of claim 8, wherein the msgA of the two-step RACH procedure isreceived from the UE, and multiple UEs share the set of RACH resourcesin a time and frequency domain.
 15. An apparatus for wirelesscommunication, comprising: a memory; and at least one processor coupledto the memory and configured to: receive, from a base station, anindication of resources in time and frequency allocated for randomaccess channel (RACH) communication with the base station, wherein theindication of resources comprises a set of RACH resources, wherein theset of RACH resources is mapped to a time frequency resource grid withrespect to a synchronization signal block (SSB) based on at least one ofa center frequency of a RACH resource or a number of physical resourceblocks (PRBs) within each RACH resource in the set of RACH resources,wherein the indication of resources is based on a mapping index for theset of RACH resources mapped to the time frequency resource grid andindexed in a sequential order, wherein the mapping index maps at leastone of the set of RACH resources to the time frequency resource grid;and transmit, to the base station, a message A (msgA) of a two-step RACHprocedure based on the indication of resources received from the basestation.
 16. The apparatus of claim 15, wherein the indication ofresources is based on a raster of candidate locations for the set ofRACH resources.
 17. The apparatus of claim 15, wherein the indicationcomprises a starting location of the set of RACH resources and a numberof the RACH resources comprised in the set of RACH resources.
 18. Theapparatus of claim 15, wherein the indication comprises a startinglocation of the set of RACH resources and an ending location of the setof RACH resources.
 19. The apparatus of claim 15, wherein the set ofRACH resources comprises a number of the RACH resources that arecontiguous in time or frequency.
 20. The apparatus of claim 15, whereinthe set of RACH resources is interlaced in time or frequency within aresource grid spanning a system bandwidth in frequency and at least oneslot in time.
 21. The apparatus of claim 15, wherein the msgA of thetwo-step RACH procedure is transmitted to the base station, and multipleUEs share the set of RACH resources in a time and frequency domain. 22.An apparatus for wireless communication, comprising: a memory; and atleast one processor coupled to the memory and configured to: transmit,to a user equipment (UE), an indication of resources in time andfrequency allocated for random access channel (RACH) communication withthe UE, wherein the indication of resources comprises a set of RACHresources, wherein the set of RACH resources is mapped to a timefrequency resource grid with respect to a synchronization signal block(SSB) based on at least one of a center frequency of a RACH resource ora number of physical resource blocks (PRBs) within each RACH resource inthe set of RACH resources, wherein the indication of resources is basedon a mapping index for the set of RACH resources mapped to the timefrequency resource grid and indexed in a sequential order, wherein themapping index maps at least one of the set of RACH resources to the timefrequency resource grid; and receive, from the UE, a message A (msgA) ofa two-step RACH procedure based on the indication of resourcestransmitted to the UE.
 23. The apparatus of claim 22, wherein theindication of resources is based on a raster of candidate locations forthe set of RACH resources.
 24. The apparatus of claim 22, wherein theindication comprises a starting location of the set of RACH resourcesand a number of the RACH resources comprised in the set of RACHresources.
 25. The apparatus of claim 22, wherein the indicationcomprises a starting location of the set of RACH resources and an endinglocation of the set of RACH resources.
 26. The apparatus of claim 22,wherein the set of RACH resources comprises a number of the RACHresources that are contiguous in time or frequency.
 27. The apparatus ofclaim 22, wherein the set of RACH resources is interlaced in time orfrequency within a resource grid spanning a system bandwidth infrequency and at least one slot in time.
 28. The apparatus of claim 22,wherein the msgA of the two-step RACH procedure is received from the UE,and multiple UEs share the set of RACH resources in time and frequencydomain.